Technical Field
The present disclosure relates to mobile devices, such as mobile telephone terminals. Specifically, the present disclosure relates to mobile devices provided with a near field communication function and a wireless charging function. Moreover, the present disclosure is related to a combo coil module that is incorporated in such a mobile device, the combo coil combining a near field communication antenna coil for near field communication, and a wireless power receiving coil for wireless charging.
Description of Related Art
Mobile devices in recent years have incorporated near field communication (NFC) functions. NFC is an international communication standard using a 13.56 MHz electromagnetic wave. NFC performs data communication at a range typically within 10 cm.
In recent years, the function of a non-contact IC card has been incorporated into mobile devices. A non-contact IC card technique called FeliCa (trademark) from Sony Corporation has been developed as a non-contact IC card function. A non-contact IC card may typically utilize a 13.56 MHz electromagnetic wave between readers/writers, and perform communication at 100 to 400 kbps at about a 10 cm range. The communication standard used by FeliCa is NFC. That is, NFC is an upward compatibility of FeliCa. In the present disclosure, the antenna for NFC/FeliCa is generally called an NFC antenna.
Generally, an NFC antenna mounted in a mobile device may be influenced by metals, such as a battery pack that exists in the vicinity of the NFC antenna. One measure for mitigating the influence of metallic elements on the NFC antenna is by shielding the battery pack magnetically by arranging a magnetic sheet between, e.g., the NFC antenna and the battery pack which is arranged behind the NFC antenna. Another measure for mitigating the influence of metallic elements on an NFC antenna is by arranging the NFC antenna at a position substantially away from the battery pack such that the antenna does not experience the influence of the metallic elements.
Furthermore, when a mobile device has a function of wirelessly charging a battery mounted inside the mobile device, a wireless power receiving coil may be arranged in the mobile device. The wireless power receiving coil typically has a specified plane coil structure of about a 30 mm diameter.